Matched peripheral dose and dose-volume histograms: Fusing an old concept with modern technology for brachytherapy prescription

Modern imaging and dosimetry are invaluable for defining a three-dimensional target when tumors can be visualised; it is far more difficult to identify a target volume after the tumors has been excised. The Paris system was devised prior to the introduction of modern high dose rate (HDR) equipment, and cannot utilize the flexibility that it offers. A prescription point, such as 'a depth of 10 mm', is often used as a target surrogate, but the localisation of this 'point' is arbitrary. Small variations in its selection may result in large differences in the delivered dose. To achieve this aim, an old concept, matched peripheral dose (MPD) was revived, and fused with dose-volume histograms DVH) generated by modern dosimetry technology. The results are that an objective technique was formulated for retrospectively assessing delivered dose, or prospectively prescribing treatment for tumors bed brachytherapy. (author)